Improving social awareness about the advantages and adverse effects of stem cell therapy is required based on research that examines both sides of the coin, short and long term advantages and disadvantages. One of the most challenging parts of the process of incorporating stem cells into clinical practice is controlling their division and differentiation potentials.

Sometimes, their potential for uncontrolled growth will make these cells tumorigenic. Additionally, while stem cells can easily differentiate into a wide variety of cells, a paracrine effect controlled activity, being in an appropriate medium will cause abnormal differentiation leading to treatment failure.

Another caveat in this process is immunorejection and the potentially deleterious new methods developed with arresting immune surveillance to enhance systemic acceptance and utility of stem cell implants. Incampacitating the immune system with antibodies that block normal T-cell activation even temporarily may win the battle over immunorejection but lose the war over tumours growing unobstructed since the immune soldiers are paralyzed. Stem cells offer tantalizing prospects to anti-ageing and regenerative medicine. They are used for skin repair, hair growth and the maintenance of various adult tissues and organs. They can modulate numerous incurable diseases such as heart conditions, diabetes, brain injuries etc [162, 163].

The coin has two sides, and stem cells advocates focus on the positive one– the miracles of transplanting stem cells to cure a variety of diseases, without bona fide evidence from large well-controlled studies or longitudinal research with proven validity and reliability that will accurately delineate the long term advantages and disadvantages of these procedures. Even mesenchymal stem cells (MSCs) which are relatively safe from malignant transformations, and do not stir up ethical controversies, have limited clinical usefulness due to cellular senescence that impairs their differentiation potential leading to uncontrolled proliferation and tumour formation.

Ageing is not the only process that diminishes the function of MSCs. Their phenotype is affected by the donors heterogeneity, the culture condition, and the cell passage in the body. The necessary process for stem cells functionality, cellular differentiation depends on the increased ratio between:

1) Mitochondrial differential that promotes activity, and

2)Nuclear differentiation that prevents activity.

Embryonic stem cells have a low ratio and therefore a compromised differentiation potential, due to low mitochondrial content. Mutations in nuclear genes coding for mitochondrial proteins decrease the differentiation rate leading to neoplastic growth, another word for tumours that may be benign or malignant cancers. Proliferation and differentiation are like a seesaw: when one goes up the other goes down. Differentiation decreases with age, therefore, cellular proliferation should increase, which is why cancers are usually age related. However the gen eral understanding in the stem cells industry is that the body’s supply of stem cells decreases with age.

This research does not accurately examine

a) whether it is proliferation that decreases which may be actually beneficial because differentiation will be more efficient

b) whether senescence affects the overall funtionality of stem cells leading to compromised utilization of stem cells’ implants If either is true then stem cell implants would prove to have more disadvantages than advantage

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